My teacher gave the task to solder a circuit to supply and connect my Arduino uno, to a 12 V,2A and ~5nm holding torque, stepper motor.

Im a bit puzzled. How can i connect my arduino to this. I looked for switched power supplys, consisting of mainly diodes and capacitors to make smooth voltage and a transistor (who is supposed to get the arduino pwn?) to control the transformator.

http://www.technic3d.com/article/pics/144/schalt_nt.jpg

Would this work?

Edit: Since its a bipolar motor i would need 2 of theese supplys for each motor inductance, right?